Endocrine therapy intended to reduce recurrence in women with breast cancer is also associated with side effects such as vasomotor symptoms (VMS), commonly known as hot flashes. These symptoms can affect whether patients remain on therapy intended to treat their underlying breast cancer and impact healthcare resource utilization, costs, and cancer outcomes. Evidence is lacking on the association of VMS from endocrine therapy and whether patients stop, remain, or experience other treatment changes.
This study will examine the feasibility of conducting a cohort study in CPRD in women with breast cancer treated with endocrine therapy and have subsequent VMS. The feasibility will examine how well VMS are captured in the CPRD database and assess how endocrine therapy use is captured with respect to documenting whether patients stay on treatment, stop treatment, or experience changes such as reducing amount prescribed.
As this study uses electronic health record data, there may be different ways to determine whether patients experience VMS beyond a recorded diagnosis, such as being prescribed recommended treatments for menopause. The feasibility will also assess if VMS can be defined using a combination of diagnoses and prescription records. Finally, the feasibility will examine how well breast cancer recurrence can be determined in the database.
The findings of the feasibility will determine whether CPRD has adequate data to conduct a full study to investigate the impact of VMS on breast cancer patients continuing endocrine therapy, as well as the impact on healthcare use, costs, and cancer outcomes.
Evidence is lacking on the impact of vasomotor symptoms (VMS) in women with breast cancer (BC) in the UK primary care setting who start endocrine therapy (ET), which includes tamoxifen, aromatase inhibitors (AI), and gonadotropin releasing hormone (GnRH) analogs. This study will examine the feasibility of a cohort study on women with BC who have VMS after starting ET.
The aim of the feasibility is to determine how well VMS is defined in the CPRD database and different operational definitions for VMS including a combination of diagnosis and prescription records. Second, the feasibility will examine how ET prescriptions are captured, to inform algorithmic considerations for defining treatment outcomes such as adherence, persistence, and dose changes. Finally, the feasibility will examine how well breast cancer recurrence can be operationalized in the database.
The study population will meet the following criteria:
1. Adult female patients with at least one drug exposure to adjuvant ET (tamoxifen, AI, GnRH analogs)
2. BC diagnosis at any time before first ET exposure
The feasibility will assess in the study population:
1. Patient counts, baseline characteristics of those with and without VMS diagnosis
2. Patient counts with recommended VMS treatments such as hormone therapy, serotonin reuptake inhibitors (SSRIs), by VMS status
3. Drug Issue data for ET, hormone therapy, SSRIs: Data completeness, average quantities, average durations, dosing information, route of administration, data transformations needed for adherence, persistence, and dose change measures.
4. Patient counts with BC recurrence or second BC diagnosis during the study period, and temporality of BC recurrence relative to initial diagnosis, ET start, and VMS
The intended public health benefit of this research in a future study is to highlight for women with breast cancer and physicians on the association of VMS on long term ET use and subsequent adverse breast cancer outcomes.
Induced vasomotor symptoms; vasomotor symptoms; menopause, recording of endocrine therapy use; breast cancer recurrence
Joehl Nguyen - Chief Investigator - Bayer U.S. LLC
Joehl Nguyen - Corresponding Applicant - Bayer U.S. LLC
Carina Dinkel-Keuthage - Collaborator - Bayer AG
Eren Elci - Collaborator - Bayer AG
Victoria Banks - Collaborator - Bayer AG
Yik Ming Fung - Collaborator - Bayer AG